Table 1. Characteristics of the Study Population.
| Characteristic | No. (%) of Patients in Group | P Value | |||||
|---|---|---|---|---|---|---|---|
| All (N = 60 321) | No NBUVB (n = 20 105)a | NBUVB <50 (n = 20 106)b | NBUVB 50-99 (n = 9702)c | NBUVB 100-199 (n = 6226)d | NBUVB ≥200 (n = 4182)e | ||
| Age group, y | |||||||
| 20-29 | 6357 (10.5) | 2119 (10.5) | 2119 (10.5) | 1138 (11.7) | 644 (10.3) | 337 (8.1) | <.001 |
| 30-39 | 9069 (15.0) | 3021 (15.0) | 3024 (15.0) | 1511 (15.6) | 966 (15.5) | 547 (13.1) | |
| 40-49 | 12 351 (20.5) | 4117 (20.5) | 4117 (20.5) | 1945 (20.0) | 1251 (20.1) | 921 (22.0) | |
| 50-59 | 15 215 (25.2) | 5071 (25.2) | 5072 (25.2) | 2418 (24.9) | 1559 (25.0) | 1095 (26.2) | |
| 60-69 | 11 112 (18.4) | 3704 (18.4) | 3704 (18.4) | 1729 (17.8) | 1150 (18.5) | 825 (19.7) | |
| 70-79 | 5337 (8.8) | 1779 (8.8) | 1779 (8.8) | 835 (8.6) | 558 (9.0) | 386 (9.2) | |
| ≥80 | 880 (1.5) | 294 (1.5) | 291 (1.4) | 126 (1.3) | 98 (1.6) | 71 (1.7) | |
| Sex | |||||||
| Male | 26 704 (44.3) | 8899 (44.3) | 8901 (44.3) | 4237 (43.7) | 2768 (44.5) | 1899 (45.4) | .45 |
| Female | 33 617 (55.7) | 11 206 (55.7) | 11 205 (55.7) | 5465 (56.3) | 3458 (55.5) | 2283 (54.6) | |
Abbreviation: NBUVB, narrowband UV-B.
a
Patients who had not received phototherapy.
b
Patients who had received less than 50 sessions.
c
Patients who had received 50 to 99 sessions.
d
Patients who had received 100 to 199 sessions.
e
Patients who had received 200 or more sessions.